diff --git a/ChangeLog.d/alignment-perf.txt b/ChangeLog.d/alignment-perf.txt
index 8ab649bbc..7a8e6fb4a 100644
--- a/ChangeLog.d/alignment-perf.txt
+++ b/ChangeLog.d/alignment-perf.txt
@@ -1,4 +1,8 @@
 Features
-   * Improvements to the code used to access unaligned and byte-swapped memory
-     reduce code size and improve performance (depending on compiler and target
+   * General performance improvements by accessing multiple bytes at a time.
+     Fixes #1666.
+   * Improvements to use of unaligned and byte-swapped memory, reducing code
+     size and improving performance (depending on compiler and target
      architecture).
+Changes
+   * Mixed-endian systems are explicitly not supported any more.